An earthquake powerful enough to rank among the top 10 strongest earthquakes on record struck off the coast of Russia on July 29, triggering a series of tsunami warnings and watches.
The earthquake measured an incredible magnitude of 8.8. For context, the Michigan Technological University says magnitude 8.0 or greater earthquakes can cause massive damage and destroy communities.
The U.S. Tsunami Warning System (tsunami.gov) will be updating its guidance as experts learn more about the threat, including maps showing what areas face what risks. In the minutes and hours after a major earthquake, tsunami assessments change as researchers track data from buoy and other interments.
Latest updates: Live coverage of Tsunami risk after 8.8 earthquake off Russia
Here's what each of the alert levels mean, according to the agency:
